Woodwind musical instruments, e.g., saxophones and clarinets, and other devices such as bird calls, utilize the vibration of a reed in response to a flow of air to generate a tone. These reeds include natural cane reeds and synthetic reeds. Tone generation in general depends on proper reed vibration. The reed is typically placed in contact with a mouthpiece to cover an opening or window. The reed is held in place by an adjustable clamp or ligature that surrounds the mouthpiece and the reed. Variations in the mouthpiece and ligature affect the vibration of the reed and, therefore, the performance or tone of the device or instrument.
The essential function of the mouthpiece of a woodwind instrument is to provide support for the reed over an aperture that allows the reed to vibrate and to direct the energy from the reed vibration through the aperture and into the bore of the instrument. The function and performance of a mouthpiece is influenced by the arrangement and geometry of the facing around the aperture as well as tone chamber below the reed, which defines the route from the aperture to the bore. The facing was conventionally a flat surface on the mouthpiece surrounding the aperture, and the reed is placed in contact with this flat surface, covering the aperture. The facing includes the aperture, called a window, and the window is surrounded by a table on one end, two side rails extending from the table and a tip rail opposite the table. The reed functions as a reed valve during vibration, opening and closing the window.
The reed includes a heel end that is positioned over the table of the mouthpiece. The bottom surface of the reed extends along the top surfaces of side rails that extend from the table along either side of the window that exposes the tone chamber. The reed tapers to a reed tip that is positioned over the tip rail of the mouthpiece. The tip rail extends between the side rails at the end of the tone chamber opposite the table. An aperture is formed by the reed tip and the tip rail. This aperture also extends along the reed a portion of the length of each side rail from the tip rail. This aperture or gap is an abrupt opening. The abrupt opening induces a high acoustic impedance and generates the formation of intense shock fronts that inhibit the flow of the airstream through the aperture between the reed tip and the tip rail. The shock fronts extend from the bottom of the reed to the side rail top surfaces and tip rail and are generally perpendicular to the direction of propagation of air and vibrations through the aperture and into the tone chamber.
The generated shock fronts degrade the resonance level of the woodwind instrument. The performance level of the woodwind instrument in terms of the characteristics of power, sonority, intonation and articulation is also degraded. In addition to the shock front generated by the tip aperture, the shape of the tone chamber below the reed can produce additional shock fronts that further degrade the performance level of the woodwind instrument. Therefore, modifications to the shape of the mouthpiece around the tip rail and in the tone chamber are desired that improve the performance level of the instrument.